The geochemistry of Martian meteorites provides a wealth of information about the solid planet and the surface and atmospheric processes that occurred on Mars. The degree to which Martian magmas may have assimilated crustal material, thus altering the geochemical signatures acquired from their mantle sources, is unclear1. This issue features prominently in efforts to understand whether the source of light rare-earth elements in enriched shergottites lies in crustal material incorporated into melts1,2 or in mixing between enriched and depleted mantle reservoirs3. Sulphur isotope systematics offer insight into some aspects of crustal assimilation. The presence of igneous sulphides in Martian meteorites with sulphur isotope signatures indicative of mass-independent fractionation suggests the assimilation of sulphur both during passage of magmas through the crust of Mars and at sites of emplacement. Here we report isotopic analyses of 40 Martian meteorites that represent more than half of the distinct known Martian meteorites, including 30 shergottites (28 plus 2 pairs, where pairs are separate fragments of a single meteorite), 8 nakhlites (5 plus 3 pairs), Allan Hills 84001 and Chassigny. Our data provide strong evidence that assimilation of sulphur into Martian magmas was a common occurrence throughout much of the planet’s history. The signature of mass-independent fractionation observed also indicates that the atmospheric imprint of photochemical processing preserved in Martian meteoritic sulphide and sulphate is distinct from that observed in terrestrial analogues, suggesting fundamental differences between the dominant sulphur chemistry in the atmosphere of Mars and that in the atmosphere of Earth4.
Subscribe to Journal
Get full journal access for 1 year
only $3.83 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Jones, J. H. Isotopic relationships among the shergottites, the nakhlites, and Chassigny. Proc. Lunar Planet. Sci. Conf. 19, 465–474 (1989)
Herd, C. D. K., Borg, L. E., Jones, J. H. & Papike, J. J. Oxygen fugacity and geochemical variations in the Martian basalts: implications for Martian basalt petrogenesis and the oxidation state of the upper mantle of Mars. Geochim. Cosmochim. Acta 66, 2025–2036 (2002)
Borg, L. E., Nyquist, L. E., Taylor, L. A., Wiesmann, H. & Shih, C.-Y. Constraints on Martian differentiation processes from Rb-Sr and Sm-Nd isotopic analyses of the basaltic shergottite QUE 94201. Geochim. Cosmochim. Acta 61, 4915–4931 (1997)
Farquhar, J., Bao, H. & Thiemens, M. Atmospheric influence of Earth’s earliest sulfur cycle. Science 289, 756–758 (2000)
Farquhar, J., Savarino, J., Jackson, T. L. & Thiemens, M. H. Evidence of atmospheric sulphur in the Martian regolith from sulphur isotopes in meteorites. Nature 404, 50–52 (2000)
Farquhar, J., Kim, S.-T. & Masterson, A. Implications from sulfur isotopes of the Nakhla meteorite for the origin of sulfate on Mars. Earth Planet. Sci. Lett. 264, 1–8 (2007)
McSween, H. Y. What we have learned about Mars from SNC meteorites. Meteoritics 29, 757–779 (1994)
Gao, X. & Thiemens, M. H. Isotopic composition and concentration of sulfur in carbonaceous chondrites. Geochim. Cosmochim. Acta 57, 3159–3169 (1993)
Rai, V. K. & Thiemens, M. H. Mass independently fractionated sulfur components in chondrites. Geochim. Cosmochim. Acta 71, 1341–1354 (2007)
Mikouchi, T. et al. Yamato 980459: mineralogy and petrology of a new shergottite-related rock from Antarctica. Antarct. Meteorite Res. 17, 13–34 (2004)
Gao, X. & Thiemens, M. H. Systematic study of sulfur isotopic composition in iron meteorites and the occurrence of excess 33S and 36S. Geochim. Cosmochim. Acta 55, 2671–2679 (1991)
Rai, V. K., Jackson, T. L. & Thiemens, M. H. Photochemical mass-independent sulfur isotopes in achondritic meteorites. Science 309, 1062–1065 (2005)
Labidi, J., Cartigny, P. & Moreira, M. Non-chondritic sulphur isotope composition of the terrestrial mantle. Nature 501, 208–211 (2013)
Gross, J. et al. Petrography, mineral chemistry, and crystallization history of olivine-phyric shergottite NWA 6234: a new melt composition. Meteorit. Planet. Sci. 48, 854–871 (2013)
Irving, A. J., Herd, C. D. K., Gellissen, M., Kuehner, S. M. & Bunch, T. E. Paired fine-grained, permafic olivine-phyric shergottites Northwest Africa 2990/5960/6234/6710: trace element evidence for a new type of Martian mantle source or complex lithospheric assimilation process. Meteorit. Planet. Sci. 46, A108 (2011)
Rubin, A. E. et al. Los Angeles: the most differentiated basaltic Martian meteorite. Geology 28, 1011 (2000)
Warren, P. H., Greenwood, J. P. & Rubin, A. E. Los Angeles: a tale of two stones. Meteorit. Planet. Sci. 39, 137–156 (2004)
Day, J. M. D., Taylor, L. A., Floss, C. & McSween, H. Y., Jr Petrology and chemistry of MIL 03346 and its significance in understanding the petrogenesis of nakhlites on Mars. Meteorit. Planet. Sci. 41, 581–606 (2006)
Mittlefehldt, D. W. ALH 84001, a cumulate orthopyrocenite member of the Martian meteorite clan. Meteoritics 29, 214–221 (1994)
Greenwood, J. P., Mojzsis, S. J. & Coath, C. D. Sulfur isotopic compositions of individual sulfides in Martian meteorites ALH 84001 and Nakhla: implications for crust-regolith exchange on Mars. Earth Planet. Sci. Lett. 184, 23–35 (2000)
Shearer, C. K., Layne, G. D., Papike, J. J. & Spilde, M. N. Sulfur isotopic systematics in alteration assemblages in Martian meteorite Allan Hills 84001. Geochim. Cosmochim. Acta 60, 2921–2926 (1996)
Mikouchi, T., Miyamoto, M., Koizumi, E., Makishima, J. & McKay, G. Relative burial depths of nakhlites: an update. Proc. Lunar Planet. Sci. Conf. 37, abstr. 1865 (2006)
Jambon, A. et al. Northwest Africa 5790. Top sequence of the nakhlite pile. Proc. Lunar Planet. Sci. Conf. 41, 1696 (2010)
Mikouchi, T. & Miyamoto, M. Comparative cooling rates of nakhlites as inferred from iron-magnesium and calcium zoning of olivines. Proc. Lunar Planet. Sci. Conf. 31, abstr. 1343 (2002)
Udry, A., McSween, H. Y., Lecumberri-Sanchez, P. & Bodnar, R. J. Paired nakhlites MIL 090030, 090136, and 03346: insights into the Miller Range parent meteorite. Meteorit. Planet. Sci. 47, 1575–1589 (2012)
Bridges, J. C. & Grady, M. M. Evaporite mineral assemblages in the nakhlite (Martian) meteorites. Earth Planet. Sci. Lett. 176, 267–279 (2000)
Hallis, L. J. & Taylor, G. J. Comparisons of the four Miller Range nakhlites, MIL 03346, 090030, 090032 and 090136: textural and compositional observations of primary and secondary mineral assemblages. Meteorit. Planet. Sci. 46, 1787–1803 (2011)
Shirai, N. & Ebihara, M. Chemical characteristics of nakhlites: implications to the geological setting for nakhlites. Proc. Lunar Planet. Sci. Conf. 39, 1643 (2008)
Shih, C.-Y., Nyquist, L. E., Reese, Y. & Jambon, A. Sm-Nd isotopic studies of two nakhlites, NWA 5790 and Nakhla. Proc. Lunar Planet. Sci. Conf. 41, 1367 (2010)
McSween, H. Y. in The Martian Surface: Composition, Mineralogy, and Physical Properties (ed. Bell, J. F. ) 383–396 (Cambridge Univ. Press, 2008)
Baroni, M., Savarino, J., Cole-Dai, J., Rai, V. K. & Thiemens, M. H. Anomalous sulfur isotope compositions of volcanic sulfate over the last millennium in Antarctic ice cores. J. Geophys. Res. 113, D20112 (2008)
Basu Sarbadhikari, A., Day, J. M. D., Liu, Y., Rumble, D. & Taylor, L. A. Petrogenesis of olivine-phyric shergottite Larkman Nunatak 06319: implications for enriched components in Martian basalts. Geochim. Cosmochim. Acta 73, 2190–2214 (2009)
Hulston, J. R. & Thode, H. G. Variations in the S33, S34, and S36 contents of meteorites and their relation to chemical and nuclear effects. J. Geophys. Res. 70, 3475–3484 (1965)
Farquhar, J., Savarino, J., Airieau, S. & Thiemens, M. H. Observation of wavelength-sensitive mass-independent sulfur isotope effects during SO2 photolysis: implications for the early atmosphere. J. Geophys. Res. 106, 32829–32839 (2001)
Forrest, J. & Newman, L. Silver-110 microgram sulfate analysis for the short time resolution of ambient levels of sulfur aerosol. Anal. Chem. 49, 1579–1584 (1977)
Thode, H. G., Monster, J. & Dunford, H. B. Sulphur isotope geochemistry. Geochim. Cosmochim. Acta 25, 159–174 (1961)
Mayer, B. & Krouse, H. R. in Handbook of Stable Isotope Analytical Techniques Vol. 1 (ed. de Groot, P. ) 538–596 (Elsevier Science, 2004)
Labidi, J., Cartigny, P., Birck, J. L., Assayag, N. & Bourrand, J. J. Determination of multiple sulfur isotopes in glasses: a reappraisal of the MORB δ34S. Chem. Geol. 334, 189–198 (2012)
We acknowledge the Meteorite Working Group, L. Welzenbach, T. McCoy, S. Ralew, M. N. Rao, L. Nyquist, J. Zipfel, C. Smith, H. Kojima, A. Treiman, T. Bunch and B. Zanda for providing meteorite samples analysed in this study. We also thank P. Piccoli for assistance with electron microprobe analyses. The manuscript benefited from independent reviews by M. Thiemens, P. Cartigny, S. Ono, D. Johnston and B. Wing during revision. The UCLA ion microprobe facility is partly supported by a grant from the US National Science Foundation Instrumentation and Facilities Program. This work was supported by NASA Cosmochemistry grants NNX09AF72G and NNX13AL13G to J.F.
The authors declare no competing financial interests.
Extended data figures and tables
Asterisks indicate samples for which not all fractions were recovered. Uncertainty (1 s.d.) is estimated as ±2% of values.
Extended Data Figure 3 Plot of Δ33S versus δ34S showing arrays for mixing between compound A and compound B (solid black line), and Rayleigh fractionation with formation of compound B at the expense of compound A.
The dotted black line is the array of compositions formed for residual reactant (A). The dotted grey line is the array of compositions formed for the instantaneous product (B). The solid grey line is the array of compositions formed for the accumulated product (B). The calculations assumed fractionation factors between compound B and compound A of 0.9739409 for 34S/32S and 0.9864855 for 33S/32S, which are similar to those observed between sulphide and sulphate at 250 °C. This plot illustrates how non-zero Δ33S can be produced by mixing and Rayleigh fractionation involving fractionated endmembers. The scarcity of evidence for highly fractionated δ34S in the data collected for Martian meteorites argues against this process as an origin for the non-zero Δ33S in the nakhlites, and by extension, the other Martian meteorites.
Extended Data Figure 4 Back-scattered electron (BSE) image and Ca, Ti, P, S, Fe, Cl and K X-ray maps of MIL 03346, section 118.
Note the fine filaments of phosphate-rich materials and pervasive high-K content of the intercumulus matrix. Sulphides are restricted to the intercumulus matrix and range in size from ≥20 μm to <1 μm. Scale bars, 100 μm.
Extended Data Figure 5 Reflected-light images of representative sulphide grains in MIL 03346, sections 6, 93, 104 and 132.
All images, except k and l (mag., ×20), are at ×50 magnification. Images a, b, c, f, i and l are from MIL 03346, section 6, and images d and e, h and k, and g are from MIL 03346, sections 104, 93 and 132, respectively.
Extended Data Figure 6 Back-scattered electron images of sulphides in MIL 03346, section 6 (c) and MIL 03346, section 93 (a, b).
Note the fractured appearance of the sulphides and occurrence of Fe(OH) in the cracks and along the edges of matrix-exposed sulphides, as well as the presence of a sulphate ‘plume’ in b, giving a smoky appearance to the enclosing matrix material. Scale bars, 100 μm.
About this article
Cite this article
Franz, H., Kim, S., Farquhar, J. et al. Isotopic links between atmospheric chemistry and the deep sulphur cycle on Mars. Nature 508, 364–368 (2014) doi:10.1038/nature13175
Syneruptive incorporation of martian surface sulphur in the nakhlite lava flows revealed by S and Os isotopes and highly siderophile elements: implication for mantle sources in Mars
Geochimica et Cosmochimica Acta (2019)
Meteoritics & Planetary Science (2019)
Determination of the water content and D/H ratio of the martian mantle by unraveling degassing and crystallization effects in nakhlites
Geochimica et Cosmochimica Acta (2019)
Use of Isotope Effects To Understand the Present and Past of the Atmosphere and Climate and Track the Origin of Life
Angewandte Chemie International Edition (2019)
Planetary and Space Science (2019)